Thickened acidic, hard surface cleaning and disinfecting compositions particularly useful for ceramic surfaces

ABSTRACT

Acidic, thickened cleaning and disinfecting compositions which exhibit good long term shelf stability, are particularly effective in the removal of limescale from hard surfaces, and which are effective against gram positive and gram negative bacteria. The compositions comprise one or more nonionic surfactants; one or more quaternary ammonium surfactant compounds having germicidal properties; an acid mixture comprising formic acid and one or more water soluble organic acids, particularly water soluble organic acids selected from the group consisting of: lactic acid, citric acid, glycolic acid and where the formic acid and one or more water soluble organic acids are present in a weight ratio of formic acid: formic acid:water soluble organic acid(s) of 1:0.1-10; a cellulose based thickening composition; optionally but desirably a one or more conventional additives such as a coloring agent, fragrance or pH adjusting agent; and, water. The compositions may also include further conventional adjuvants such as perfumes and coloring agents in minor amounts. The compositions feature surprisingly good viscosity retention over time notwithstanding the presence of formic acid and cellulose based thickeners in the compositions.

The present invention relates to thickened cleaning and disinfectingcompositions which are acidic in nature, and which exhibit goodcleaning, disinfecting and long term stability.

While the prior art has provided various compositions directed tocleaning and disinfecting hard surfaces, particularly lavatory surfacesthere is yet a continuing need in the art for thickened aqueouscompositions which provide: satisfactory cleaning especially oflimescale deposits from metal, enamel and porcelain surfaces as found onlavatory fixtures, disinfection of hard surfaces and good long termstability of the thickened compositions.

The present invention provides stable thickened aqueous acidic hardsurface cleaning and disinfecting composition which comprises:

one or more nonionic surfactants, particularly linear primary alcoholethoxylates;

one or more quaternary ammonium surfactant compounds having germicidalproperties;

an acid mixture comprising formic acid and one or more water solubleorganic acids, particularly water soluble organic acids selected fromthe group consisting of: lactic acid, glycolic acid and citric acid andparticularly where the acid mixture include formic acid and at least oneother water soluble organic acid wherein these acids are present in aweight ratio of formic acid:water soluble organic acids of 1:0.1-10;

a cellulose based thickening composition;

optionally but desirably a pH adjusting agent, fragrance, coloringagent;

and, water.

The aqueous acidic hard surface cleaning and disinfecting compositionmay further include minor amounts, i.e., less than a combined totalamount of 10%wt., of conventional additives including but not limitedto: colorants such as pigments and dyes; fragrances and perfumes, pHadjusting agents as well as other conventional additives. Mostdesirably, these compositions are effective against both gram positiveand gram negative bacteria.

The present invention also provides a method for cleaning (especiallythe removal of limescale deposits) and disinfecting from metal, enameland porcelain surfaces as found on lavatory fixtures.

The compositions include one or more nonionic surfactants. These arewell known, and any of these are expected to be useful in the inventivecompositions. Exemplary useful nonionic surfactants include condensationproducts of alkylene oxide groups with an organic hydrophobic compound,such as an aliphatic or alkyl aromatic compound. Further exemplaryuseful nonionic surfactants include the polyoxyethylene ethers of alkylaromatic hydroxy compounds, e.g., alkylated polyoxyethylene phenols,polyoxyethylene ethers of long chain aliphatic alcohols, thepolyoxyethylene ethers of hydrophobic propylene oxide polymers, and thehigher alkyl amine oxides. Also contemplated as useful are ethoxylatedalkyl phenols such as octylphenolethoxylates and nonylphenolethoxylates.

Preferred nonionic surfactants are ethoxylated alcohols. The compoundsare well known and may be formed by condensation of an alcohol, ormixtures thereof, with sufficient ethylene oxide to produce a compoundhaving a polyoxyethylene. Preferably the number of ethylene oxide unitsare present in an amount sufficient to insure solubility of the compoundin an aqueous composition of this invention or in any dilution thereof.Desirably, the ethoxylated alcohols are produced by condensation ofabout 4-20, more preferably 6-18 moles of ethylene oxide with 1 mole ofthe linear primary aliphatic alcohol. The aliphatic alcohol may belinear or may be branched, and may be a primary, secondary or tertiaryalcohol (including by way of non-limiting example: decyl alcohol,dodecyl alcohol, tridecyl alcohol, hexadecyl alcohol, octadecyl alcohol,and the like). As known to those skilled in the art, the number of molesof ethylene oxide which are condensed with one mole of aliphatic alcoholdepends upon the molecular weight of the hydrophobic portion of thecondensation product. The aliphatic alcohols are desirably a primary,secondary or tertiary aliphatic alcohol having about 10-20, andpreferably 11-17, carbon atoms, and most preferably is an alcohol having12-16 carbon atoms Especially preferably the nonionic surfactant of thepresent inventive compositions is the condensation product of linear orbranched C₁₂-C₁₆ aliphatic alcohols, especially C₁₂-C₁₆ linear aliphaticalcohols or mixtures thereof, with sufficient ethylene oxide to providean average of from 6-12 moles of ethylene oxide per molecule. Mostpreferably the nonionic surfactant constituent consists solely of linearor branched C₁₂-C₁₆ aliphatic alcohols with 6-9 moles of ethylene oxideper molecule.

The nonionic surfactant is present in any effective amount, butgenerally is present in an amount of up to about 10% by weight, based onthe total weight of the composition. Desirably the nonionic surfactantis present in an amount of from about 0.01%wt. to about 8%wt, and mostdesirably is present in an amount of from about 0.1%wt. to about 5%wt.

The compositions according to the invention include one or morequaternary ammonium surfactant compounds having germicidal properties;these compounds provide a sanitizing effect. Particularly usefulquaternary ammonium compounds and salts thereof include quaternaryammonium germicides which may be characterized by the general structuralformula:

where at least one of R₁, R₂, R₃ and R₄ is a hydrophobic, aliphatic,aryl aliphatic or aliphatic aryl radical of from 6 to 26 carbon atoms,and the entire cation portion of the molecule has a molecular weight ofat least 165. The hydrophobic radicals may be long-chain alkyl,long-chain alkoxy aryl, long-chain alkyl aryl, halogen-substitutedlong-chain alkyl aryl, long-chain alkyl phenoxy alkyl, aryl alkyl, etc.The remaining radicals on the nitrogen atoms other than the hydrophobicradicals are substituents of a hydrocarbon structure usually containinga total of no more than 12 carbon atoms. The radicals R₁, R₂, R₃ and R₄may be straight chained or may be branched, but are preferably straightchained, and may include one or more amide or ester linkages. Theradical X may be any salt-forming anionic radical.

Exemplary quaternary ammonium salts within the above description includethe alkyl ammonium halides such as cetyl trimethyl ammonium bromide,alkyl aryl ammonium halides such as octadecyl dimethyl benzyl ammoniumbromide, N-alkyl pyridinium halides such as N-cetyl pyridinium bromide,and the like. Other suitable types of quaternary ammonium salts includethose in which the molecule contains either amide or ester linkages suchas octyl phenoxy ethoxy ethyl dimethyl benzyl ammonium chloride,N-(laurylcocoaminoformylmethyl)-pyridinium chloride, and the like. Othervery effective types of quaternary ammonium compounds which are usefulas germicides include those in which the hydrophobic radical ischaracterized by a substituted aromatic nucleus as in the case oflauryloxyphenyltrimethyl ammonium chloride, cetylaminophenyltrimethylammonium methosulfate, dodecylphenyltrimethyl ammonium methosulfate,dodecylbenzyltrimethyl ammonium chloride, chlorinateddodecylbenzyltrimethyl ammonium chloride, and the like.

Preferred quaternary ammonium compounds which act as germicides andwhich are found useful in the practice of the present invention includethose which have the structural formula:

wherein R₂ and R₃ are the same or different C₁-C₁₂alkyl, or R₂ isC₁₂₋₁₆alkyl, C₈₋₁₈alkylethoxy, C₈₋₁₈alkylphenolethoxy and R₃ is benzyl,and X is a halide, for example chloride, bromide or iodide, or is amethosulfate counterion. The alkyl groups recited in R₂ and R₃ may bestraight chained or branched, but are preferably substantially linear.

Particularly useful quaternary germicides include compositions whichinclude a single quaternary, as well as mixtures of two or moredifferent quaternary. Particularly useful quaternary germicides includeBARDAC® 205M, and BARDAC® 208M or BTC® 885which is described to be ablend of alkyl dimethyl benzyl ammonium chlorides; BARDAC® 2050 andBARDAC® 2080 or BTC® 818 which is described to be based ondialkyl(C₈-C₁₀)dimethyl ammonium chloride; BARDAC® 2250 and BARDAC® 2280or BTC® 1010 which is described to be a composition which includesdidecyl dimethyl ammonium chloride; BARDAC® LF and BARDAC® LF 80 whichis described to be based on dioctyl dimethyl ammonium chloride; BARQUAT®MB-50, HYAMINE® 3500, BARQUAT® MB-80, BTC® 835, BTC® 8358 or BTC® 65 USPeach described to be based on alkyl dimethyl benzyl ammonium chloride;BARQUAT® MX-50, BARQUAT® MX-80, BTC® 824 or BTC® 8248 each described tobe a composition based on alkyl dimethyl benzyl ammonium chloride;BARQUAT® OJ-50, BARQUAT® OJ-80, BTC® 2565, or BTC®& 2658 each describedto be a composition based on alkyl dimethyl benzyl ammonium chloride;BARQUAT® 4250, BARQUAT® 4280, BARQUAT® 4250Z, BARQUAT® 4280Z, BTC® 2125,or BTC® 2125M each described to be a composition based on alkyl dimethylbenzyl ammonium chloride and/or alkyl dimethyl ethyl benzyl ammoniumchloride; BARQUAT® MS-100 or BTC® 324-P-100 each described to be basedon myristyl dimethyl benzyl ammonium chloride; HYAMINE® 2389 describedto be based on methyl dodecyl benzyl ammonium chloride and/or methyldodecyl xylene-bis-trimethyl ammonium chloride; HYAMINE® 1622 describedto be an aqueous solution of benzethonium chloride; HYAMINE® 3500-NF orBTC® 50 each described to be based on alkyl dimethyl benzyl ammoniumchloride; as well as BARQUAT® 1552 or BTC® 776 described to be based onalkyl dimethyl benzyl ammonium chloride and/or dialkyl methyl benzylammonium chloride. (Each of these recited materials are presentlycommercially available from Lonza, Inc., Fairlawn, N.J. and/or fromStepan Co., Northfield Ill.).

These quaternary ammonium surfactant compounds may be present in anyeffective amount, but and are effective in amounts from as little as0.001%wt. Typically, these compounds are present in amounts of from0.01-10% by weight, based on the total weight of the composition.Desirably these compounds are present in amounts from 0.01-7%wt, moredesirably from 0.1-5%wt., and most desirably from 0.1-3%wt.

These quaternary ammonium compounds are usually provided in an alcoholsuch as a C₁-C₆ alcohol (i.e., ethanol, n-propanol, isopropanol,n-butanol, sec-butanol) or in an aqueous/alcohol mixture containing suchalcohols. While these alcohols are present in only a very minor amountas they are supplied as part of the quaternary ammonium compounds it isbelieved they contribute to the antimicrobial efficacy of the invention.Therefore, it is preferred that up to about 1%wt. of a C₁-C₆ alcohol,preferably 0.001-1%wt., more preferably 0.01-0.75%wt. be present in theinventive compositions.

In the cleaning compositions according to the invention, the quaternaryammonium compound constituent is required to be present in amounts whichare effective in exhibiting satisfactory germicidal activity againstselected bacteria sought to be treated by the cleaning compositions.Such efficacy may be achieved against less resistant bacterial strainswith only minor amounts of the quaternary ammonium compounds beingpresent, while more resistant strains of bacteria require greateramounts of the quaternary ammonium compounds in order to destroy thesemore resistant strains. The quaternary ammonium compound need only prepresent in germicidally effective amounts, but may be present in amountsfrom 0.01%-10% wt. based on the total weight of the composition of whichthey form a part. Generally, effective “hospital strength” germicidalefficacy meeting current EPA guidelines is provided when the quaternaryammonium compounds are present in an amount of from about 0.05%wt. toabout 5%wt. Desirably in the compositions of the instant invention, thequaternary ammonium compounds is present in an amount of from 0.05%wt.to about 3%wt, based on the total weight of the inventive compositionsbeing taught herein.

An essential feature of the inventive compositions is an acid mixturecomprising formic acid and one or more water soluble organic acids,particularly water soluble organic acids. The acid mixture may bepresent in any effective amount, but desirably is not present in amountsof more than about 10%wt. based on the total weight of the compositions.Desirably the acid mixtures form from 0.01-10%wt., more desirably from0.1-10%wt. of the compositions. The water soluble organic acids includeat least two carbon atoms, and include at least one carboxyl group(—COOH) in its structure. Particularly useful as water soluble organicacids are formic acid and an acid selected from the group consisting of:lactic acid, citric acid, and glycolic acid. The formic acid and thefurther water soluble organic acid in the acid mixture are present in aweight ratio of formic acid:water soluble organic acids of 1:0.1-10, anddesirably 1:0.25-2.5, and more desirably from 1:0.5-1.75. Particularlyadvantageous ratios are indicated in the Examples. While various organicacids such as and including these acids may have been used in the past,usually singly, the present inventors have surprisingly discovered anapparent synergistic effect from the acid mixtures described. It hasbeen surprisingly discovered that the long term stability of thecellulose containing compositions is achieved when the formic acid ispresent with one or more water soluble organic acids (or water solublesalt forms thereof), particularly in the weight ratios described. In theprior art, cellulose thickeners have not been typically used in thepresence of formic acid, which acid is very desirable as it isparticularly effective in removing limescale. According to the presentinvention, the use of one or more water soluble organic acids inconjunction with formic acid substantially reduces the loss of viscosityof the thickened compositions to a degree greater than would beexpected. This is surprising as the presence of the acids in suchcompositions is expected to quickly degrade other constituents which maybe present, especially thickeners such as described below. This isparticularly true in compositions which contain formic acid inconjunction with cellulose based materials as formic acid is known toquickly degrade such cellulose based materials.

This surprising benefit is frequently very apparent when formic acid ispresent in conjunction with two (or more) different water solubleorganic acids. This has been to be particularly true where the ratio ofthe formic acid: (total weight of the two or more different watersoluble organic acids) is a ratio of: 1:(0.1-10). Where three differentwater soluble organic acids are present, desirably these are present ina weight ratio of formic acid:first water soluble organic acid:secondwater soluble organic acid of 1:0.1-10:0.1-10, especially when these arepresent in a weight ratios of: 1:0.25-2.5:0.25-2.5, and most especiallyin a weight ratio of 1:0.5-1.75:0.5-1.75. Particularly advantageousratios are indicated in the Examples.

The presence of formic acid in conjunction with at least one furtherwater soluble organic acids in the weight ratios described above providegood cleaning, and have been found to suffer a reduced loss of viscosityunder the conditions of accelerated aging testing at elevatedtemperatures, particularly under the test protocol described in theexamples. This is particularly important as the compositions are acidicin nature.

The inventive compositions desirably feature low odor, are virtuallytransparent (in the absence of coloring agents) ever after hightemperature stability testing, and are easy to disperse onto surfaces tobe cleaned and disinfected.

As noted, the compositions of the invention are thickened and have aviscosity greater than water. The actual degree of thickening isdependent on the amount of thickener included in a composition.Thickeners which may be used are cellulose based thickeners includingbut not limited to: methyl cellulose, methylethyl cellulose,hydroxymethyl cellulose, hydroxyethyl cellulose, carboxymethylcellulose, and the like. Generally the thickener is present in not morethan about 10%wt. based on the total weight of the composition of whichit forms a part. Desirably the thickener is present in an amount of from0.01-5%wt., and more desirably from 0.01-2%wt. Starch based thickeners,including so called modified starch based thickeners as frequentlyencountered in the foods industry are also contemplated as being useful.

The compositions of the invention are acidic, and exhibit a pH of lessthan 7, more preferably about 4.5 and less and most preferably from3-4.5. Whereas the presence of the acid mixture described above willimpart acidity to the composition, it is frequently desirable to includea buffer or pH adjusting agent to the compositions to maintain thecompositions approximately at a desired pH (or pH range). Exemplaryuseful pH buffers include inorganic and organic buffering agent, andespecially include alkali metal and alkaline earth metal hydroxides suchas sodium hydroxide and potassium hydroxide. Others not described heremay also be used. Particularly preferred is sodium hydroxide which iswidely available at low cost, and is effective.

Such materials as described above are each individually known to theart, many of which are described in McCutcheon's Emulsifiers andDetergents (Vol. 1), McCutcheon's Functional Materials (Vol. 2), NorthAmerican Edition, 1991; Kirk-Othmer, Encyclopedia of ChemicalTechnology, 3rd Ed., Vol. 22, the contents of which are hereinincorporated by reference For any particular composition describedabove, any optional ingredients should be compatible with the otheringredients present.

As is noted above, the compositions according to the invention areaqueous in nature. Water is added to order to provide to 100% by weightof the compositions of the invention. The water may be tap water, but ispreferably distilled and is most preferably deionized water. If thewater is tap water, it is preferably substantially free of anyundesirable impurities such as organics or inorganics, especiallyminerals salts which are present in hard water which may thusundesirably interfere with the operation of the constituents present inthe aqueous compositions according to the invention.

The compositions may be made by simply mixing measured amounts of theindividual constituents into water, at room temperature under constantstirring until a homogenous mixture is attained. In a preferred method,a first premixture is made by mixing together the nonionic and fragranceconstituents. A second premixture is made by mixing the water, cellulosethickener and optionally, sodium hydroxide to form a homogeous mixture.Thereafter, the first premixture is added to the second premixture,after which the remaining constituents are added, and mixing continuesuntil a homogenous mixture is attained.

According to certain preferred embodiments of the invention there areprovided thickened aqueous acidic hard surface cleaning and disinfectingcompositions which consist essentially of:

0.1-10%wt. one or more nonionic surfactants;

0.1-10%wt. of one or more quaternary ammonium surfactant compoundshaving germicidal properties;

0.001-1% of a C₁-C₆ alcohol;

0.1-10%wt. an acid mixture comprising formic acid and one or more watersoluble organic acids, particularly water soluble organic acids selectedfrom the group consisting of: lactic acid, glycolic acid and citric acidand particularly where the acid mixture include formic acid and at leastone other water soluble organic acid wherein these acids are present ina weight ratio of formic acid:water soluble organic acids of 1:0.1-10;

0.01-5%wt. a cellulose based thickening composition;

optionally up to 10%wt. of one or more optional constituents,

with the remaining balance to 100%wt. of water.

The thickened aqueous acidic hard surface cleaning and disinfectingcomposition according to the invention is desirably provided as a readyto use product which may be directly applied to a hard surface. By wayof example, hard surfaces include surfaces composed of refractorymaterials such as: glazed and unglazed tile, brick, porcelain, ceramicsas well as stone including marble, granite, and other stones surfaces;glass; metals; plastics e.g. polyester, vinyl; fiberglass, Formica®,Corian® and other hard surfaces known to the industry. Hard surfaceswhich are to be particularly denoted include those associated withkitchen environments and other environments associated with foodpreparation. The inventive compositions are particularly useful incleaning and disinfecting lavatory fixtures such as shower stalls,bathtubs and bathing appliances (racks, curtains, shower doors, showerbars) toilets, bidets, wall and flooring surfaces especially those whichinclude refractory materials and the like. The inventive compositionsespecially particularly useful in the cleaning and disinfecting oflavatory fixtures, especially toilets and bidets. They may be packagedin any suitable container particularly flasks or bottles, includingsqueeze-type bottles, as well as bottles provided with a spray apparatuswhich is used to dispense the composition by spraying.

In a yet further aspect of the invention there is provided an thickenedaqueous composition which includes a cellulose based thickener, an acidmixture comprising formic acid and one or more water soluble organicacids, particularly water soluble organic acids selected from the groupconsisting of: lactic acid, glycolic acid and citric acid andparticularly where the acid mixture include formic acid and at least oneother water soluble organic acid wherein these acids are present in aweight ratio of formic acid:water soluble organic acids of 1:0.1-10; andoptionally one or more detersive sufactants.

The compositions according to the invention, including certain preferredembodiments of the invention are presented in the following examples.

EXAMPLES

A number of formulations according to the invention (indicated asExamples, “E”) as well as several comparative examples (indicated asComparatives, “C”) were produced. Each of these were made were mixingthe constituents outlined on Table 1 by adding the individualconstituents into a beaker of deionized water at room temperature (68°F., 20° C.) which was stirred with a conventional magnetic stirring rod.Stirring continued until the formulation was homogenous in appearance.It is to be noted that the constituents might be added in any order, butit is preferred that water be the initial constituent provided to amixing vessel or apparatus as it is the major constituent and additionof the further constituents thereto is convenient. Also, it isconvenient to disperse the cellulose thickener into a premixture with aquantity of water, and to add this premixture to the beaker. The exactcompositions of the example formulations are listed on Table 1, below.

Evaluation of Shelf Stability:

Formulations according to the invention and described on Table 1 wereevaluated in order to determine their initial viscosity. The weightsindicated on Table 1 indicate the amount of the named constituent, andare to be understood to represent 100%wt. actives of each namedconstituent. The source of the named constituents are described in moredetail in the following Table. Each of the constituents on Table 1.

Table (Constituents) linear alcohol ethoxylate supplied by GENAPOL26-L-60, a linear C₁₂- C₁₆ alcohol ethoxylate, with an average of 7.3ethylene oxide groups per molecule (100% wt. actives) quaternaryammonium supplied by BTC-888 (Stepan Chem. Co.) a chlorides blend ofdialkyl dimethyl benzyl ammonium chloride, and alkyl dimethyl benzylammonium chloride (80% wt. actives) which includes 10% wt. ethanolhydroxyethyl cellulose supplied by CELLOSIZE QP-100MH from Union CarbideCo. (Danbury, CT) (100% wt. actives) formic acid aqueous, technicalgrade, Aldrich Co. or other supplier (94% wt. actives) citric acidaqueous, technical grade, Aldrich Co. or other supplier (100% wt.actives) glycolic acid aqueous, technical grade, Aldrich Co. or othersupplier (57% wt. actives) fragrance and dye proprietary compositions oftheir respective manufacturers di water deionized water

All viscosity measurements were performed on aliquots of a formulationat room temperature with a Brookfield Viscometer, fitted with a LV-2spindle at a rotational speed of 60 rpm at 22° C. Viscosity measurementresults are reported in centipoise at on Tables 2A, 3A below.Formulations were placed in sealed glass containers, and subjected to anaccelerated aging test wherein the formulations were maintained at 120°F. (48.5° C.) for a period of 6 weeks. At weekly intervals, aliquots ofeach formulation were taken and used to determine the viscosity in themanner outlined above. Similarly, the results are reported on Tables 2A,3A below. The cumulative total loss of viscosity, at weekly intervals isreported on Tables 2B and 3B below.

TABLE 1 Ratio: Formic acid: 1^(st) α-hydroxy Ratio: organic acid:quaternary Formic acid: 2^(nd) α- linear alcohol ammonium hydroxy ethylfragrance formic citric glycolic deionized α-hydroxy hydroxy InitialFormulation: ethoxylate chlorides cellulose and dye acid acid acid waterorganic acid organic acid pH C1 0.5 1.1 0.5 0.35 2.35 0 0 to 100 1:01:0:0 3.50 C2 0.5 1.1 0.5 0.35 0 2.5 0 to 100  —  — 3.52 C3 0.5 1.1 0.50.35 0 0 1.43 to 100  —  — 3.52 C4 0.5 1.1 0.5 0.35 0 1.25 0.71 to 100 —  — 3.55 E1 0.5 1.1 0.5 0.35 1.175 0 0.71 to 100 1:0.6 1:0:0.6 3.50 E20.5 1.1 0.5 0.35 1.175 1.25 0 to 100 1:1.06 1:1.06:0 3.51 E3 0.5 1.1 0.50.35 0.78 0.83 0.47 to 100 1:1.66 1:1.06:0.6 3.52 E4 0.5 1.1 0.5 0.350.78 0.83 0.47 to 100 1:1.66 1:1.06:0.6 3.51 C5 0.5 1.1 0.5 0.35 2.35 00 to 100 1:0 1:0:0 4.04 C6 0.5 1.1 0.5 0.35 0 2.5 0 to 100  —  — 4.05 C70.5 1.1 0.5 0.35 0 0 1.43 to 100  —  — 4.04 C8 0.5 1.1 0.5 0.35 0 1.250.71 to 100  —  — 4.03 E5 0.5 1.1 0.5 0.35 1.175 1.25 0 to 100 1:1.061:1.06:0 4.00 E6 0.5 1.1 0.5 0.35 1.175 0 0.71 to 100 1:0.6 1:0:0.6 4.01E7 0.5 1.1 0.5 0.35 0.78 0.83 0.47 to 100 1:1.66 1:1.06:0.6 4.04 E8 0.51.1 0.5 0.35 0.78 0.83 0.47 to 100 1:1.66 1:1.06:0.6 4.03

TABLE 2A (pH = 3.5) Week 1 Week 2 Week 3 Week 4 Week 5 Week 6Formulation: Initial pH Initial Viscosity (cps) (cps) (cps) (cps) (cps)(cps) C1 3.50 407.0 331.0 294.0 272.0 245.0 224.0 197.0 C2 3.52 417.0334.0 282.0 264.0 210.0 175.0 150.0 C3 3.52 438.0 364.0 342.o 334.0302.0 272.0 267.0 C4 3.55 426.0 339.0 322.0 301.0 267.0 257.0 202.0 E13.50 396.0 324.0 309.0 286.0 262.0 261.0 214.0 E2 3.51 416.0 369.0 309.0296.0 259.0 222.0 205.0 E3 3.52 406.0 337.0 311.0 289.0 261.0 250.0195.0 E4 3.51 417.0 346.0 322.0 306.0 265.0 234.0 209.0

TABLE 2B (pH = 3.5) Cumulative % Cumulative % Cumulative % Cumulative %Cumulative % Cumulative % Viscosity Viscosity Viscosity ViscosityViscosity Viscosity loss @ loss @ loss @ loss @ loss @ loss @Formulation: Initial pH Initial Viscosity week 1 week 2 week 3 week 4week 5 week 6 C1 3.50 407.0 18.67% 27.76% 33.17% 39.80% 40.05% 51.60% C23.52 417.0 19.90% 32.37% 36.69% 49.64% 58.03% 64.03% C3 3.52 438.016.89% 21.92% 23.74% 31.05% 37.90% 39.04% C4 3.55 426.0 20.42% 24.41%29.34% 37.32% 39.67% 52.58% E1 3.50 396.0 18.18% 21.97% 27.78% 33.84%34.09% 45.96% E2 3.51 416.0 11.30% 25.72% 28.85% 37.74% 46.63% 50.72% E33.52 406.0 17.00% 23.40% 28.82% 35.71% 38.42% 51.97% E4 3.51 417.017.03% 22.78% 26.62% 36.45% 43.88% 43.88%

TABLE 3A (pH = 4) Week 1 Week 2 Week 3 Week 4 Week 5 Week 6 Formulation:Initial pH Initial Viscosity (cps) (cps) (cps) (cps) (cps) (cps) C5 4.04424.0 329.0 269.0 254.0 209.0 174.0 158.0 C6 4.05 417.0 362.0 341.0316.0 292.0 272.0 240.0 C7 4.04 446.0 384.0 384.0 384.0 356.0 336.0336.0 C8 4.03 429.0 386.0 379.0 354.0 342.0 344.0 294.0 E5 4.00 409.0381.0 351.0 356.0 322.0 299.0 297.0 E6 4.01 441.0 397.0 387.0 394.0359.0 339.0 344.0 E7 4.04 438.0 397.0 392.0 379.0 362.0 354.0 321.0 E84.03 424.0 379.0 379.0 359.0 336.0 336.0 299.0

TABLE 3B (pH = 4) Cumulative % Cumulative % Cumulative % Cumulative %Cumulative % Cumulative % Viscosity Viscosity Viscosity ViscosityViscosity Viscosity loss @ loss @ loss @ loss @ loss @ loss @Formulation: Initial pH Initial Viscosity week 1 week 2 week 3 week 4week 5 week 6 C5 4.04 424.0 22.41% 36.56% 40.09% 50.71% 58.96% 62.74% C64.05 417.0 13.19% 18.23% 24.22% 29.98% 34.77% 42.45% C7 4.04 446.013.90% 13.90% 13.90% 20.18% 24.66% 24.66% C8 4.03 429.0 10.02% 11.66%17.48% 20.28% 19.81% 31.47% E5 4.00 409.0  6.85% 14.18% 12.96% 21.27%26.89% 27.38% E6 4.01 441.0  9.98% 12.24% 10.66% 18.59% 23.13% 22.00% E74.04 438.0  9.36% 10.50% 13.47% 17.35% 19.18% 26.71% E8 4.03 424.010.61% 10.61% 15.33% 20.75% 20.75% 29.48%

Subsequent to this accelerated aging test, all of the formulations wereobserved to each be a colored, substantially transparent single phasemixture with good flow properties; bulk phase separation was notobserved to occur.

Evaluation of Antimicrobial Efficacy:

A formulation according to the invention was prepared from the followingconstituents:

Example A 0.50% hydroxyethyl cellulose 0.50% linear C₁₂-C₁₆ alcoholethoxylate, with an average of 7.3ethylene oxide groups per molecule1.50% quaternary ammonium chloride 1.10% formic acid 1.40% glycolic acid˜1.0% sodium hydroxide ˜0.4% fragrance and dyes to 100% deionized water

The weight percentages for Example A indicate the actual weight of theindicated materials, which were supplied from the constituents were thesame as used to form the formulations indicated on Table 1, above. Thisformulation was evaluated in order to evaluate its antimicrobialefficacy against Staphylococcus aureus (gram positive type pathogenicbacteria) (ATCC 6538), Salmonella choleraesuis (gram negative typepathogenic bacteria) (ATCC 10708), and Pseudomonas aeruginosa (ATCC15442). The testing was performed in accordance with the protocolsoutlined in “Use-Dilution Method”, Protocols 955.14, 955.15 and 964.02described in Chapter 6 of “Official Methods of Analysis”, 16^(th)Edition, of the Association of Official Analytical Chemists; “Germicidaland Detergent Sanitizing Action of Disinfectants”, 960.09 described inChapter 6 of “Official Methods of Analysis”, 15^(th) Edition, of theAssociation of Official Analytical Chemists; or American Society forTesting and Materials (ASTM) E 1054-91 the contents of which are hereinincorporated by reference. This test is also commonly referred to as the“AOAC Use-Dilution Test Method”.

As is appreciated by the skilled practitioner in the art, the results ofthe AOAC Use-Dilution Test Method indicates the number of testsubstrates wherein the tested organism remains viable after contact for10 minutes with a test disinfecting composition/total number of testedsubstrates (cylinders) evaluated in accordance with the AOACUse-Dilution Test. Thus, a result of “0/60” indicates that of 60 testsubstrates bearing the test organism and contacted for 10 minutes in atest disinfecting composition, 0 test substrates had viable (live) testorganisms at the conclusion of the test. Such a result is excellent,illustrating the excellent disinfecting efficacy of the testedcomposition.

Results of the antimicrobial testing of the Example A formulation areindicated on Table 4, below. The reported results indicate the number oftest cylinders with live test organisms/number of test cylinders testedfor each example formulation and organism tested.

TABLE 4 Antimicrobial Testing Staphylococcus Salmonella Pseudomonasaureus choleraesuis aeruginosa 0/60 0/60 0/60

As may be seen from the results indicated above, the compositionsaccording to the invention provide excellent disinfection of hardsurfaces.

While the invention is susceptible of various modifications, it is to beunderstood that specific embodiments thereof have been shown by way ofexample in the drawings which are not intended to limit the invention tothe particular forms disclosed; on the contrary the intention is tocover all modifications, equivalents and alternatives falling within thescope and spirit of the invention as expressed in the appended claims.

What is claimed is:
 1. Thickened acidic hard surface cleaning anddisinfecting composition comprising: one or more nonionic surfactants;one or more quaternary ammonium surfactant compounds having germicidalproperties; an acid mixture comprising formic acid and one or more watersoluble organic acids wherein these acids are present in a weight ratioof formic acid:water soluble organic acids of 1:0.1-10; a cellulosebased thickening composition; optionally to 10%wt. of one or moreoptional constituents; and, water.
 2. The composition according to claim1 wherein the water soluble organic acids are selected from the groupconsisting of: lactic acid, glycolic acid and citric acid.
 3. Thecomposition according to claim 1 wherein the acid mixture comprisescitric acid.
 4. The composition according to claim 1 wherein the acidmixture comprises glycolic acid.
 5. The composition according to claim 1wherein the nonionic surfactant is a linear alcohol ethoxylate.
 6. Thecomposition according to claim 1 wherein the acid mixture contains atleast formic acid, and at least two further different water solubleorganic acids.
 7. The composition according to claim 6 wherein the acidmixture contains formic acid, citric acid and glycolic acid.
 8. Thecomposition according to claim 1 wherein the formic acid and one or morewater soluble organic acids are present in a weight ratio of formicacid:water soluble organic acids of 1:0.25-2.5.
 9. The compositionaccording to claim 1 which further comprises up to 1%wt. of a C₁-C₆alcohol.
 10. Thickened aqueous acidic hard surface cleaning anddisinfecting composition according to claim 1 which consists essentiallyof: 0.1-10%wt. one or more nonionic surfactants; 0.001-10%wt. of one ormore quaternary ammonium surfactant compounds having germicidalproperties; 0.001-1% of a C₁-C₆ alcohol; 0.1-10%wt. of an acid mixturecomprising formic acid and one or more water soluble organic acids wherethe formic acid and one or more water soluble organic acids are presentin a weight ratio of formic acid:water soluble organic acids of1:0.1-10; 0.01-5%wt. a cellulose based thickening composition;optionally up to 10%wt. of one or more optional constituents, with theremaining balance to 100%wt. of water.
 11. The composition according toclaim 10 wherein the formic acid and one or more water soluble organicacids are present in a weight ratio of formic acid:water soluble organicacids of 1:0.25-2.5.
 12. The composition according to claim 10 whereinthe composition further includes colorants, fragrances, perfumes, or pHadjusting agents.
 13. A thickened aqueous composition according to claim1 which further includes one or more further detersive surfactants. 14.A process for cleaning limescale from a hard surface comprising theprocess step of: contacting the hard surface having limescale thereonwith a cleaning effective amount of the composition according to claim 1to clean limescale present therefrom.
 15. A process for cleaninglimescale from a hard surface comprising the process step of: contactingthe hard surface having limescale thereon with a cleaning effectiveamount of the composition according to claim 10 to clean limescalepresent therefrom.
 16. A thickened acidic hard surface cleaning anddisinfecting composition which comprises: 0.1-10%wt. of one or morenonionic surfactants; 0.001-10%wt. of one or more quaternary ammoniumsurfactant compounds having germicidal properties; 0.1-10%wt. of an acidmixture consisting of formic acid and one or more water soluble organicacids wherein these acids are present in a weight ratio of formicacid:water soluble organic acids of 1:0.1-10; 0.01-5%wt. of a cellulosebased thickening composition; 0-10%wt. of one or more optionalconstituents; and, water.
 17. The composition according to claim 16wherein the water soluble organic acids are selected from the groupconsisting of: lactic acid, glycolic acid and citric acid.
 18. Thecomposition according to claim 16 wherein the acid mixture contains atleast formic acid, and at least two further different water solubleorganic acids.
 19. The composition according to claim 16 wherein theacid mixture contains formic acid, citric acid and glycolic acid. 20.The composition according to claim 16 wherein the formic acid and one ormore water soluble organic acids are present in a weight ratio of formicacid:water soluble organic acids of 1:0.25-2.5.
 21. The compositionaccording to claim 16 wherein the nonionic surfactant is a linearalcohol ethoxylate.
 22. The composition according to claim 16 whichfurther comprises up to 1%wt. of a C₁-C₆ alcohol.
 23. The compositionaccording to claim 16 which comprises one or more further detersivesurfactants.
 24. Thickened aqueous acidic hard surface cleaning anddisinfecting composition according to claim 16 which consistsessentially of: 0.1-10%wt. one or more nonionic surfactants;0.001-10%wt. of one or more quaternary ammonium surfactant compoundshaving germicidal properties; 0.001-1% of a C₁-C₆ alcohol; 0.1-10%wt. ofan acid mixture consisting of formic acid and one or more water solubleorganic acids where the formic acid and one or more water solubleorganic acids are present in a weight ratio of formic acid:water solubleorganic acids of 1:0.1-10; 0.01-5%wt. a cellulose based thickeningcomposition; 0-10%wt. of one or more optional constituents, with theremaining balance to 100%wt. of water.
 25. The composition according toclaim 24 wherein the formic acid and one or more water soluble organicacids are present in a weight ratio of formic acid:water soluble organicacids of 1:0.25-2.5.